A "pure" UBI (that entirely replaces welfare) would distribute earnings upwards.

"This implies that were we to eliminate current income support programs and apply the funds towards a pure UBI, there would be a relative redistribution from low-earners to zero earners, but the first-order effects would be a massive distribution up the earnings distribution, along with a redistribution from the elderly and disabled towards those who are neither, primarily but not exclusively those without children."